The term 'upward thrust' can be summarized as a BOOST or an increase in power. It is often used to describe the force that propels an object upward, such as a rocket or an airplane. This force is generated by the engines of the vehicle and is usually accompanied by a loud noise. Upward thrust is also used to describe the force that pushes an object away from the ground, such as a parachute or a hot air balloon. In this case, the force is generated by the air pressure created by the balloon or parachute.